Crank is hard to turn after rebuild even w/out head installed.

[dsm-onster]

I'm rebuilding my brother's engine. He bought a blown 1991 GSX and a 1991 6-bolt N/T block.

His turbo rods and pistons from the blown motor checked out quite nicely. So we swapped them into the N/T block. The N/T bearings looked very, very, so very good!!! So I kept them and installed them on to the piston rods going to their respective crank journal. I, of course, lubed everything midswap. Except for the cylinder walls. I swapped new oem rings as well.

The n/t block rods had a little play (lateral or forward-and-back: along the same line as the crank). The engine was running before I took it apart. But w/ the turbo rods installed, there is zero "lateral" play. The crank is "hard to turn" I can't turn it except w/ a wrench of significant length. . . I need quite a bit of torque. Then as I'm turning it, she becomes easier to turn over. . . Considering what I've done to this block, Is this ok? Of course w/ the head installed, it becomes a little harder to turn over, but I can still do it. Again, it gets easier after I turn it over one revolution. But if I wait a while, it becomes very difficult again (need an extension on the wrench handle).

 

[92awddsm]

I personally would have to feel it before I can make a determination. It could be normal tension from the rings or it could be because a rind twisted when installing the pistons. I wish this had come up earlier. I just passed through Bowling Green on my way to and from LaPlata last Sunday. I would offer to come up this weekend but I am leaving for one more trip to the beach this weekend.

Anyway, without being there, my best suggestion would be to pull all 4 pistons out, inspect rings for damage, and make sure the crank spins freely with pistons and rods removed. If all is good, reinstall parts, one cylinder at a time, and spin the crank each time to get a feel of the additional tnsion from each piston. By the time you get to #4, you should have a good idea as to what it should feel like

 

[dsm-onster]

I personally would have to feel it before I can make a determination. It could be normal tension from the rings or it could be because a rind twisted when installing the pistons. I wish this had come up earlier. I just passed through Bowling Green on my way to and from LaPlata last Sunday. I would offer to come up this weekend but I am leaving for one more trip to the beach this weekend.

Anyway, without being there, my best suggestion would be to pull all 4 pistons out, inspect rings for damage, and make sure the crank spins freely with pistons and rods removed. If all is good, reinstall parts, one cylinder at a time, and spin the crank each time to get a feel of the additional tnsion from each piston. By the time you get to #4, you should have a good idea as to what it should feel like

Man! I jsut missed you!

Anyway, I pulled the pistons out because it freaked me out completely! No damage was visible. The "tension" got progresively worse as I re-installed the pistons/rods.

 

[Slo2gen]

Are the bearing tolerances right?

 

[dsm-onster]

Speaking of bearing clearances . . . My brother took out the pistons and rods while I was inside for a moment. He tapped the pistons out w/ a 1/2" extension and contacted the bearing seats of the rods a few times. There were some gouges. Picked a he!! of a time to go to the can! Could this have caused some metal at the bearing seat to rise so the bearing cannot fully seat into the rod? Thus, when the caps are tightened, the bearings mash against the crank?

. . . I'm definately going to pull the oil pan again. I'll have to pull the head too. I have the n/t 6bolt rods. I suppose I could get the wristpins pressed at any old machine shop. Can wrist pins be reused?

 

[nikkeebabee]

you probably have the rod caps on backwards...try switching those around

 

[dsm-onster]

I don't *think* I do. The O, C, or D goes to the firewall side? and the I or "-" goes toward the radiator. . .Right?

It's possible that the n/t rods were resized and thus larger bearings were used. This would put an oversized bearign w/ a standard crank and rod. . .Which would cause everythign to tightenup as I torqued the caps to spec, right? I'm going to mic the n/t rods now.

The n/t rods that came in the n/t block had a little "slop" axial w/ the crank not radial. I can't remember if this is normal. I havn't had my running engine apart in several years. . .

EDIT: does anyone know, or know where to get, the rod big-end diameter? And where in the heck do I get JUST the wrist pins?

 

[nikkeebabee]

I don't *think* I do. The O, C, or D goes to the firewall side? and the I or "-" goes toward the radiator. . .Right?

It's possible that the n/t rods were resized and thus larger bearings were used. This would put an oversized bearign w/ a standard crank and rod. . .Which would cause everythign to tightenup as I torqued the caps to spec, right? I'm going to mic the n/t rods now.

The n/t rods that came in the n/t block had a little "slop" axial w/ the crank not radial. I can't remember if this is normal. I havn't had my running engine apart in several years. . .

EDIT: does anyone know, or know where to get, the rod big-end diameter? And where in the heck do I get JUST the wrist pins?

That sounds right just make sure the caps are sitting on the rods correctly...If the cap is reversed it will make the crank hard to spin....

 

[speedmaster747]

maybe the wrong bearings are being used !

 

[dsm-onster]

Yea, I know for sure that the n/t 6-bolt rods work w/ the bearings I have and the n/t crank in this block, as it was a running engine. I'm going to swap the turbo pistons to the n/t rods. Does anyone know where I can get just the wristpins for oem 6bolt pistons?

 

[92awddsm]

I don't *think* I do. The O, C, or D goes to the firewall side? and the I or "-" goes toward the radiator. . .Right?

It's possible that the n/t rods were resized and thus larger bearings were used. This would put an oversized bearign w/ a standard crank and rod. . .Which would cause everythign to tightenup as I torqued the caps to spec, right? I'm going to mic the n/t rods now.

The n/t rods that came in the n/t block had a little "slop" axial w/ the crank not radial. I can't remember if this is normal. I havn't had my running engine apart in several years. . .

EDIT: does anyone know, or know where to get, the rod big-end diameter? And where in the heck do I get JUST the wrist pins?

When the big end is resized, all they do is grind the mating surfaces on the rod cap/rod, torque to spec, and hone the big end back to factor spec. The bearing size does not change when the rods are resized. The burs in the bearing saddle of the rod will definantely cause the bearing to be tight on the crank and will eventually destroy itself if run in that condition. I dont have the big end diameter in front of me but any machine shop can give you the specs over the phone.

The connecting rod side clearence(axial) should be roughly somewhere between .004"-.008". The book calls for up to .0098" with sevice limit being .016" but that is too loose for my taste.


As for wrist pins, they can be pressed out and pressed back in with no issues as long as whoever does it knows what they are doing. Im sure you can get replacement wrist pins from NAPA but if the wristpin needs to be replaced, 90% of the time, the piston does too.

The rods are not particularly directional, but the piston is. Small valve reliefs on top of the piston go towards the exhaust side of the engine and the larger valve reliefs have to go towards the intake side of the engine. When reinstalling the bearing caps, they need to go back onto the original rod and bearing locking tangs need to be aligned on the same side. They will not line up because they are offset to different sides of the rod bolt but the cap has to have the tang located beside the same rod bolt as the tang on the rod. Hope that makes some sense and helps you some. If you need to know anything else, just ask. I was an ASE master automotive machinist but I didnt renew my certification this past test time.

 

[dsm-onster]

When the big end is resized, all they do is grind the mating surfaces on the rod cap/rod, torque to spec, and hone the big end back to factor spec. The bearing size does not change when the rods are resized. The burs in the bearing saddle of the rod will definantely cause the bearing to be tight on the crank and will eventually destroy itself if run in that condition. I dont have the big end diameter in front of me but any machine shop can give you the specs over the phone.

The connecting rod side clearence(axial) should be roughly somewhere between .004"-.008". The book calls for up to .0098" with sevice limit being .016" but that is too loose for my taste.


As for wrist pins, they can be pressed out and pressed back in with no issues as long as whoever does it knows what they are doing. Im sure you can get replacement wrist pins from NAPA but if the wristpin needs to be replaced, 90% of the time, the piston does too.

The rods are not particularly directional, but the piston is. Small valve reliefs on top of the piston go towards the exhaust side of the engine and the larger valve reliefs have to go towards the intake side of the engine. When reinstalling the bearing caps, they need to go back onto the original rod and bearing locking tangs need to be aligned on the same side. They will not line up because they are offset to different sides of the rod bolt but the cap has to have the tang located beside the same rod bolt as the tang on the rod. Hope that makes some sense and helps you some.

Yes, this does, buddy. My brother will not be sweating bullets now. He has no money, and rooming w/ me for personal reasons (w/ his wife and small child). He needs a car on the road and chose a DSM . He wants a reliable ride for now, but something that has potential for a fun "build" in the near future.

So as long as the shop does right by the press, then both the pistons and the pins can be reused! Excellent. The pistons are installed in teh correct direction (I double checked that). And the tangs are all on one side as you mentioned. . . I didn't think I did it wrong. But having you guys as a check is what makes this forum the best tool in my shed.

I really feel that the gouges are the cause for the tight crank. I'll reinstall the n/t pistons and check the axial clearance, If it's good enough for you, then They're going in. If not the turbo rods need to be resized, leaving the pistons on them, and they will also have to be made a little more narrow as the crank rubs against the bearing caps (there is no axial clearance).

 

[92awddsm]

I really feel that the gouges are the cause for the tight crank. I'll reinstall the n/t pistons and check the axial clearance, If it's good enough for you, then They're going in. If not the turbo rods need to be resized, leaving the pistons on them, and they will also have to be made a little more narrow as the crank rubs against the bearing caps (there is no axial clearance).

Resizing the big end with the pistons attached is no problem. To do all 4, expect to pay somewhere between $45-70, depending on shop. I know a good shop that can do it with no issues but it is in Richmond, on 301, right before the 2nd 95 underpass. Its the NAPA on Chamberlain Ave. If you want to call them, the # is 804-321-6201 and ask to speak to Chris Marshall in the machine shop. Just tell him Keith Brown told you to call.

As for the side clearance on the turbo rods, do you know for a fact they have none or are you just looking at the sides and see rub marks? Best bet is to wrap a flat file will 180 grit sandpaper and lightly sand the sides of the big end of the rod. If there are any burs at the matiing surface or slight imperfections, this will take care fo them. Afterwards, bolt the rod to the crank and recheck. The n/t and turbo rods are identical in casting and size so there shouldnt be any differance between the 2.

And for the burrs in the rod, if you have another standard sized crank laying around, torque the rod to a crank outside the block and see if it is tight then also. You can also install the other 3 pistons, spin the engine to see if there is a lot of tension and then install the 4th rod that is damaged and see if anything changes. Regardless of the outcome, the burs in the rod need to be addressed. Take the same 180 grit sandpaper and barely wipe the inside of the rod. This will reveal the high spots on the rod around the divots from the extension. Chances are, that rod needs to be resized or at least stroked on the hone once to smooth it back out.

 

[dsm-onster]

Resizing the big end with the pistons attached is no problem. To do all 4, expect to pay somewhere between $45-70, depending on shop. I know a good shop that can do it with no issues but it is in Richmond, on 301, right before the 2nd 95 underpass. Its the NAPA on Chamberlain Ave. If you want to call them, the # is 804-321-6201 and ask to speak to Chris Marshall in the machine shop. Just tell him Keith Brown told you to call.

As for the side clearance on the turbo rods, do you know for a fact they have none or are you just looking at the sides and see rub marks? Best bet is to wrap a flat file will 180 grit sandpaper and lightly sand the sides of the big end of the rod. If there are any burs at the matiing surface or slight imperfections, this will take care fo them. Afterwards, bolt the rod to the crank and recheck. The n/t and turbo rods are identical in casting and size so there shouldnt be any differance between the 2.

And for the burrs in the rod, if you have another standard sized crank laying around, torque the rod to a crank outside the block and see if it is tight then also. You can also install the other 3 pistons, spin the engine to see if there is a lot of tension and then install the 4th rod that is damaged and see if anything changes. Regardless of the outcome, the burs in the rod need to be addressed. Take the same 180 grit sandpaper and barely wipe the inside of the rod. This will reveal the high spots on the rod around the divots from the extension. Chances are, that rod needs to be resized or at least stroked on the hone once to smooth it back out.

Thank you for that phone number. I will give them a call. I know where you are talking about! Isn't there a mall close by? Or is it farther down closer to the belvedere (sp?) exit, closer to monroe park and VCU. I went to school at the VCU school of engineering, so I'm familiar w/ the area.

As for the rod axial clearance on the crank. There is none because I canot fit a feeler gauge of any thickness between. But w/ the n/t pistons installed, I can flop them front-to-back enough to hear it across the yard (w/ enough force). Of course, I'll take your suggestion and use 180 grit sandpaper and lightly sand. It may help. . .



"The n/t and turbo rods are identical in casting and size so there shouldnt be any differance between the 2."

This was the reason for getting the n/t block. Other than the pistons and the oil squirters, the blocks are supposed to be identical. It even has a threaded boss for the knock sensor in the proper location. If I can do this build, I can get more 6-bolt blocks for cheap! There's lots of n/t 6-bolt blocks lying around. All w/ the big rods!

EDIT: I officially live across the bay on the eastern shore (Bloxom, VA). But, my parents live in Carmel Church VA. So I'm there VERY often. . . to see the grand kids (mine and my brothers). Anyway, I know of a reputable NAPA machine shop in salisbury, MD. This is closer to me. I'm sure they would be capable of doing what we need. . .

 

[92awddsm]

Thank you for that phone number. I will give them a call.

As for the rod axial clearance on the crank. There is none because I canot fit a feeler gauge of any thickness between. But w/ the n/t pistons installed, I can flop them front-to-back enough to hear it across the yard (w/ enough force). Of course, I'll take your suggestion and use 180 grit sandpaper and lightly sand. It may help. . .



"The n/t and turbo rods are identical in casting and size so there shouldnt be any differance between the 2."

This was the reason for getting the n/t block. Other than the pistons and the oil squirters, the blocks are supposed to be identical. It even has a threaded boss for the knock sensor in the proper location. If I can do this build, I can get more 6-bolt blocks for cheap! There's lots of n/t 6-bolt blocks lying around. All w/ the big rods!

We have 2 pick and pull scrapyards that end up with at least 1 1g n/tever week and a 1g turbo, both fwd and awd, every month. You can get a complete longblock for $89, crank for $39, block alone for like $49 I think, etc. CAP is closer to you, Circle Auto Recycling is closer to me. Here is the link http://www.chesterfieldauto.com/

One is only about an 45 mins from you, and the other is down my way which is only about 1hr 15 mins from you. I know for fact because I have been working out in Sparta, which is just outside newtown, every weekend from june to late august. Since then, I have been to LaPlata twice coming straight up 301.

 

[dsm-onster]

We have 2 pick and pull scrapyards that end up with at least 1 1g n/tever week and a 1g turbo, both fwd and awd, every month. You can get a complete longblock for $89, crank for $39, block alone for like $49 I think, etc. CAP is closer to you, Circle Auto Recycling is closer to me. Here is the link http://www.chesterfieldauto.com/

One is only about an 45 mins from you, and the other is down my way which is only about 1hr 15 mins from you. I know for fact because I have been working out in Sparta, which is just outside newtown, every weekend from june to late august. Since then, I have been to LaPlata twice coming straight up 301.

My father grew up in sparta! I know chesterfield auto. Best pick-n-pull I know of. . . I should have gone there. It would have been worth the trip. . .

 

[toyotaturbo]

Not saying that this is your problem, but I'm telling you what happened from my experience. Check your thrust bearing. I neglected mine by mistake one time (long hours once upon a time) and tried cranking it up, only to reveal that the crank bearing was completely jacked up. Engine completely froze. You could have a bad spot in your thrust bearing, which allows it to crank easily intermittently. Just an idea .

 

[dsm-onster]

That's a good idea to do regardless of how well the crank turns over. But remember that I can turn the crank just fine w/ the n/t pistons and rods.

 

[92awddsm]

Not saying that this is your problem, but I'm telling you what happened from my experience. Check your thrust bearing. I neglected mine by mistake one time (long hours once upon a time) and tried cranking it up, only to reveal that the crank bearing was completely jacked up. Engine completely froze. You could have a bad spot in your thrust bearing, which allows it to crank easily intermittently. Just an idea .

This would be felt by spinning the crank without any pistons/rods installed in the engine. Besides, you have to seat the thrust bearing before torquing the thrust cap and endplay should be measured before going any further. I personally like to have between .004-.007" crank endplay. I am not sure what factory specs are but with a 5 spd, this is what I prefer.

 

[92awddsm]

That's a good idea to do regardless of how well the crank turns over. But remember that I can turn the crank just fine w/ the n/t pistons and rods.

Thats why I started by telling you that I would have to feel it to give you an accurate answer. If I wasnt going out of town for the weekend, I would come up and check it out. But, nice weather this weekend makes it the last weekend trip to the beach for the summer.I dont think I could make it up to check it out until the following weekend and Im sure you and your brother are anxious to get it together before then.

If your dad is from sparta, Im sure you know where the old Easter Seals camp is. It was converted into a clinic for people with eating disorders. Me and a friend did all of the ceramic tile in 40something bathrooms and all of the hardwood flooring in the lobby and foyer of the new facility.

 

[dsm-onster]

Thats why I started by telling you that I would have to feel it to give you an accurate answer. If I wasnt going out of town for the weekend, I would come up and check it out. But, nice weather this weekend makes it the last weekend trip to the beach for the summer.I dont think I could make it up to check it out until the following weekend and Im sure you and your brother are anxious to get it together before then.

If your dad is from sparta, Im sure you know where the old Easter Seals camp is. It was converted into a clinic for people with eating disorders. Me and a friend did all of the ceramic tile in 40something bathrooms and all of the hardwood flooring in the lobby and foyer of the new facility.

Wow! I havn't been there in a while. . . My dad grew up on a tobacco farm on a road called Buzzard Neck road. But, he's 67 years old! Will be 68 in November. I doubt it is still called that. That was before Easter Seals.

Yea, don't worry about us. We'll meet up later or something. Hopefully w/ more than one DSM .

. . . Well, lady MacBeth summons . . .

 

[ziggo0]

Bumping an old thread because I ran into this problem. I'm currently assembling a 6 bolt bottom end, virgin crank that came with the block, 1g rods, all std sizes. When I torque the mains down the crank spins freely. I got the pistons in and tightened the nuts on the rods with a little bit of torque so I could turn the crank around, again - spins freely. However once I torque the rod nuts down - it becomes rather difficult to turn the crank. It can turn around just fine, not meeting any random places of resistance however I recall my 7 bolt being easier? What is this about the rod cap lettering facing the firewall and the - facing the radiator? Perhaps I got it backwards.

Edit/Update: Sucks that there was no replies about the letters on the caps but it turns out I either rushed it or was to tired to do things right, I had the pistons 180 degrees off. Turned them around and the cap's letters face the firewall, the "I" or - faces the radiator. Turning these around did not resolve my issue however. I loosened/torqued each rod to see if there were any changes and I narrowed it down to one rod. Pulled the rod and cleaned it again, including the surfaces (slight rust) when I noticed an odd spot on the crank...sorta like a chemical or some weird build up dropped on it. I'm in the progress of micropolishing the crank now to see if it resolves my issues but I just wanted to update this reply in case anyone comes across the same issue and wants some ideas.